Fair Value Measurements (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Assets:
Investments	$ 20	$ 11
Foreign Exchange Contracts	21	1
Total Assets at Fair Value	41	12
Liabilities:
Foreign Exchange Contracts	6	34
Total Liabilities at Fair Value	6	34
Supplemental Fair Value Information
Carrying amount — liability	7,254	5,334
Notes Payable and Overdrafts	459	406
Fixed Rate Debt, Excluding Capital Leases
Supplemental Fair Value Information
Carrying amount — liability	5,632	4,094
Fair value — liability	5,924	4,283
Notes Payable and Overdrafts	282	227
Variable Rate Debt, Excluding Capital Leases
Supplemental Fair Value Information
Carrying amount — liability	1,622	1,240
Fair value — liability	1,617	1,197
Notes Payable and Overdrafts	177	179
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)
Assets:
Investments	20	11
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	20	11
Liabilities:
Foreign Exchange Contracts	0	0
Total Liabilities at Fair Value	0	0
Supplemental Fair Value Information
Fair value — liability	6,070	4,391
Significant Other Observable Inputs (Level 2)
Assets:
Investments	0	0
Foreign Exchange Contracts	21	1
Total Assets at Fair Value	21	1
Liabilities:
Foreign Exchange Contracts	6	34
Total Liabilities at Fair Value	6	34
Significant Unobservable Inputs (Level 3)
Assets:
Investments	0	0
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	0	0
Liabilities:
Foreign Exchange Contracts	0	0
Total Liabilities at Fair Value	$ 0	$ 0